Flash socket assembly

ABSTRACT

An extremely shallow flash socket assembly for use in or with a photographic camera is constructed to receive a multilamp flash assembly having at least one array of lamps facing in a common direction and a thin, shallow connector blade adapted to be inserted into the socket assembly. The socket assembly includes novel electrical interfacing structures including a stationary set of resilient contact members constructed and arranged to register with and to engage terminals on a connector blade inserted into the socket assembly. Novel features of the electrical interfacing system and cooperating socket structures are disclosed.

United States Patent [1 1 Brandt et a1, a

11 3,748,980 [451' July 31, 1973 ]v FLASH SOCKET ASSEMBLY {75'1"'invnraigaansoa ii'iiaiiagcanassa;

David V. Cronin, Peabody; James K. Skurski, Beverly, all of Mass.

9 [73] Assignee: Polaroid Corporatiomcambridge,

Mass. I [22] Filed: Dec. 6, 1971 [21] Appl. No.: 204,834

[52] US. Cl. .Q 95/11 R, 95/11 L [51] Int. Cl. G03b 19/02 [58] Field ofSearch 95/11 L, 11 R, 11.5 R;

240/1.3,-2 C; 339/176 MP, 1 7 L, 17 LM, l7

References Cited UNITED STATES PATENTS 3,131,017 4/1964 Mittler 339/176MP X 3,639,888 2/1972 Pittman et al 339/176 MP X 2,935,725

D, 17 CF 5/1960 Fox 339/176 MP X 3,598,985 8/1971 Hamden et al. 95/11 LX Primary Examiner-Samuel S. Matthews Assistant Examiner-Kenneth C.Hutchison Attorney-Alfred E. Corrigan et al.

[57] 7 ABSTRACT An extremely shallow flash socket assembly for use in orwith a photographic camera is constructed to receive a multilamp flashassembly having at least one array of lamps facing in a common directionand a thin, shallow connector blade adapted to be inserted into thesocket assembly. The socket assembly includes novel electricalinterfacing structures including a stationary set of resilient contactmembers constructed and arranged to register with and to engageterminals on a connector blade inserted into the socket assembly. Novelfeatures of the electrical interfacing system and cooperating socketstructures are disclosed. I

7 Claims, 15 Drawing Figures PAIamtoJ m 3,748,980

SHEEI 1 OF 5 DAVID RONIN on JAMES K. SKURSKI /wwaza/mim ATTORNEYSPATENIEDJUI. 3 I ma SHFH 2 OF 5 ATTORNEYS PATENIEOJUL 3 1 I977 SHEEI 3OF 5 INVEN'IORS SON R. BRANDT D V. GRQNIN and JAMES K. SKURSKI VATTORNEYS PATENIEDJULB 1 191a SHEET t [If 5 PATENTEDMH ma SHEET 5 0F 5FIG. l3

,INVENTORS EDISON R. BRANDT DAVID M cnoum and JAMES K. SKURSKI EM wncl mATTORNEYS FLASH socxa'r ASSEMBLY BACKGROUND OF THE DISCLOSURE A newgeneration of photographic cameras has been revealed by the assignee ofthis application in recently issued patents, including U.S. Pat. Nos.3,447,437; 3,543,662; 3,561,339; and 3,587,426. These patents discloseadvanced folding cameras having an extremely high degree of compactnesswhen in their folded state.

This invention concerns, in general, certain aspects of a novel flashillumination system having broad application but intended especially foruse in or with such advanced cameras. The system utilizes as its sourceof luminous energy a disposable multilamp flash assembly having at leastone, but preferably two, arrays of lamps of common orientation, as shownand described for example, in U.S. Pat. Nos. 3,598,984 and 3,598,985. Inthis flash illumination system, the flash assembly is interfaced with aflash selecting system which selects the flash lamp or lamps to be firedwhen a firing command is received. The flash selecting system ispreferably a static electronic flash selecting circuit as shown, forexample, in U.S. Pat. No. 3,618,492, assigned to the assignee of thisinvention.

As shown in the referent U.S. Pat. Nos. 3,598,984 and 3,598,985, themultilamp flash assembly includes a support structure from which extendsa shallow, thin connector blade'carrying a set of electrical terminalsfor the lamps. The flash assembly has two back-to-back arrays of lampshaving respective sets of terminal strips disposed on opposite sides ofthe connector blade. The arrays are used in sequence by first ignitingthe lamps in one array, then disconnecting the flash assembly from theassociated flash socket, reversing the orientation of the assembly, andreconnecting the assembly in the flash socket.

This invention is particularly directed to the provision of means forelectrically interfacing such a multilamp flash assembly with a flashselecting system in or associated with a photographic camera, especiallywith r a static electronic flash selecting circuit in an ultracompactcamera as above-discussed. The electrical interfacing is accomplishedaccording to this invention in a novel flash socket assembly. Because ofthe extreme compactness of the described advanced cameras when folded,the total space available for the flash selecting system and for themeans for making the electrical interconnections between the flash lampterminals on the flash assembly and the flash selecting system is verysmall.

The requirements imposed upon the electrical interfacing system are, ingeneral, very stringent and particularly so as compounded by the extremelimitation in available space. In a very restricted space, theelectrical interfacing structures must: (1) insure electrical isolationof the individual contacts which engage the terminals on the connectorblade of a flash assembly; (2) insure accurate registration of thecontacts and lamp terminals such that the appropriate lamp terminal andno other is engaged by each contact; (3) preclude any possiblesimultaneous engagement of a contact with more than one lamp terminal;(4) insure the electrical integrity of the contact-terminal interfaces;(5) prevent any possibility that a lamp on the back of the flashassembly might inadvertently be ignited in the face of a user; (6)provide for thousands of flash assembly insertions and withdrawalswithout damage to the electrical contacts;

and (7) insure against overstressing of the contacts by the connectorblade of a flash assembly.

The flash selecting system discussed briefly above has a resistancemonitoring capability designed to detect a defective lamp of the typecharacterized by an abnormally low resistance. If the resistance of alamp having priority for ignition is sensed to have a value below apredetermined minimum value, the flash selecting system recognizes thiscondition as indicative of a faulty lamp and ,will avoid that lamp. Itis thus also extremely important that the distributed resistance in theelectrical interfacing system which connects the flash selecting systemwith the lamps in the flash lamp assembly be very low so as not tointerfere with the operation of such flash selecting systems.

OBJECTS OF THE INVENTION It is a general object of this invention toprovide an improved flash socket assembly for use in a photographicflash illumination system which employs as its source of luminous energya disposable multilamp flash assembly having at least one array of lampsof common orientation and which includes a flash selecting controlcenter which selects the lamp or lamps to be ignited when a firingcommand is given.

It is a less general object to provide such a socket assembly havingmeans for electrically interfacing the flash assembly with the socketassembly which meets and overcomes each of the above-discussedconstraints and design requirements.

It is another object to provide improved electrical interfacing meanswhich occupies very little space in an I associated camera, and which iscapable, by virtue of its extreme compactness of being accommodated inan ultra-compact camera.

It is still another object to provide a flash socket assembly includinga plurality of contact members, the socket assembly and contact membersbeing constructed and arranged such as to substantially eliminate thepossibility that a non-selected lamp might be ignited as a result ofmisregistration of a contact member with the associated terminals on theconnector blade of a flash assembly. It is another object to precludeinadvertent ignition of a plurality of lamps as might result fromsimultaneous engagement of a contact member with more than one terminal.

It is yet another object to'provide an electrical interfacing system foruse in a flash socket assembly which insures a sound electricalengagement with and only with the forwardly facing terminals on theconnector blade of a connected flash assembly; it is a further object toprovide an electrical interfacing system which is durable and reliable.

It is another object to provide an electrical interfacing system whichhas a very low distributed resistance so as not to interfere with theoperation of a cameras flash selecting system. i

It is another significant object of this invention to provide such aflash socket assembly having structures for insuring the electricalisolation and accurate positioning of the electrical contacts containedin the assembly.

It is also an object to provide an electrical interfacing system for usein a flash socket assembly including a plurality of contact members forengaging the connector blade of a flash assembly, the contact membersbeing constructed and arranged such that the force required to insertthe flash assembly into the socket assembly is less than the forcerequired to withdraw the flash assembly.

It is still another object to provide an electrical interfacing systemhaving a plurality of contact members which exert a loading force on theconnector blade of a flash assembl'ysufficiently great to retain theflash assembly securely in the socket assembly, and yet which arerelatively resistant to overstressing.

Further objects and advantagesof the invention will in part be obviousand will in part become apparent as the following description proceeds.The features of novelty which characterize the invention will be pointedout with particularity in the claims annexed to and forming a part ofthis specification.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. I is a perspective view of the front portion of a photographiccamera embodying a flash illumination system including a flash socketassembly implementing the teachings of this invention; a multilamp flashassembly adapted for connection into the socket assembly is shownexploded from the socket assembly for clarity of illustration;

FIG. 2 is a schematic view of a flash illumination system with whichthis invention is concerned;

FIG. 3 is a perspective view of a flash socket assembly incorporatingthe teachings of this invention;

FIG. 4 is a bottom view of the FIG. 3 socket assemy;

FIG. 5 is a bottom view of the FIG. 3 socket assembly similar to FIG. 4but showing a printed circuit strip pulled back to reveal the undersideof the socket body;

FIG. 6 is a side elevational view of the FIGS. 3-5 socket assembly,partially broken away;

FIG. 7 is a fragmentary perspective sectional view of the socketassembly shown in FIG. 3 as it would appear with the connector blade ofa flash assembly inserted into the socket assembly;

FIG. 8 is a fragmentary sectional view taken generally along lines 8-8in FIG. 3 as it would appear empty and with the contact members cutaway;

FIG. 9 is a fragmentary sectional view taken generally along lines 9-9in FIG. 3;

FIG. 10 is a fragmentary sectional view taken generally along lines10-10 in FIG. 3 showing the socket assembly as it would appear whenempty;

FIG. 11 is a view similar to FIG. 10 but showing the contact members asthey would appear when a flash assembly is connected in the socketassembly; and

FIGS. 12-15 are views illustrating an alternative embodiment of theinvention; FIGS. l2, l4, and are views corresponding to FIGS. 7, l0 and11; FIG. 13 is a fragmentary top view of the socket assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention is in generalconcerned with an imshallow connector blade 18 which extends downwardlytherefrom and carries on opposite faces first and second sets ofterminals for the lamps.

FIG. 1 shows the terminals as taking the form ofa set of terminal strips20 disposed in parallel along the direction in which the flash assembly10 is inserted into a socket assembly. A similar set of terminal strips(not shown) on the opposite face of the connector blade 18 areelectrically connected to the array of lamps l4 facing in thecorresponding direction (rearward in FIG. 1).

The FIG. 2 schematic diagram illustrates a flash assembly l0electrically connected to a flash selecting system 22 through aplurality of leads 24 which terminate in contact members 26 makingengagement with terminal strips 20 on the flash assembly 10. As shownclearly in FIG. 2, six terminal strips are provided for the five lampsin each array. The sixth terminal strip, designated 20a in FIG. 2, is aground terminal connected to a common ground wire for the lamps.

This invention is directed to the provision of an electrical interfacingsystem (shown schematically in FIG. 2) for interconnecting the lamps ina flash assembly with a flash selecting system. A full description ofelectrical interfacing systems according to this invention will be givenbelow.

The flash selecting system 22, shown in black box form in FIG. 2, maytake any of a variety of forms but preferably comprises a staticelectronic flash sequencing or programming circuit, as shown for examplein the above-mentioned U.S. Pat. No. 3,618,492. A flash selecting systemsuch as the system shown and described in the referent patent is capableof selecting a lamp or lamps in an operatively connected flash lampassembly according to a predetermined sequencing or other selectionprogram. A flash illumination system of the nature described has nomoving parts, may be programmed with a wide range of flash selectionprograms, is capable of automatically avoiding defective lamps, and hasmany other advantageous characteristics, as pointed out in detail in thesaid patent.

As suggested above, flash illumination systems with which this inventionis concerned have general utility in cameras of many types andconstructions; however, apparatus according to this invention is perhapsmost useful when embodied in compact cameras in which available space isat a premium. FIG. 1 shows a front portion of a folding camera 29 of aform disclosed in the above-noted patents held by the assignee of thisinvention U.S. Pat. Nos., 3,447,437; 3,543,662; 3,561,339; and3,587,426. The FIG. 1 camera 29 is illustrated as comprising a frontassembly 30 mounted to pivot into a face-down position on a back housingplate 32 when the camera is folded for storage. The front assembly 30 isshown as including an objective lens 34 having a picture-taking axis 35,a focus wheel 36 for focusing the lens 34, and a shutter actuator 38.

The front assembly 30 includes a'flash socket assembly 40 embodying theteachings of this invention; the socket assembly 40 is shown in detailin FIGS. 3-11. A boss 42 on the socket assembly 40 extends through a topwall 43 of the front assembly 30 and defines an entrance slot 44orthogonal to picture-taking axis 35 for receiving the connector blade18 of a flash assembly 10. The boss 42 is also useful for itsminimization of the amount of depth-wise space which the socket assembly40 must occupy within the camera front assembly 30.

The socket assembly 40 is illustrated as comprising blade support meansfor receiving the connector blade 18 of a flash assembly and for guidingthe blade 18 into a predetermined operative position within the socketassembly. In more detail, the blade support means is illustrated asincluding rear support surface means, shown for example in FIG. 8 as aplanar rear support surface 48, and opposed end support surfaces 50, 52.In the illustrated preferred embodiment the blade support structuresconstitute integral parts of a socket body 54 preferably composed of anelectrically insulative plastic material. The socket body 54 preferablyincludes the boss 42 as an integral part thereof in which is formed theentrance slot 44. In order to facilitate-connection of a flash assembly10 into the socket assembly 40, the socket body 54 has formed therein anoutwardly beveled mouth 56 surrounding the entrance slot 44. It isimportant that the depth of the mouth 56 be selected such' that anadequate blade guiding function is performed without unduly reducing thepurchase of the socket assembly upon a connector blade connectedtherein. Y

members 46 preferably take the form of conductors 47 printed on aflexible sheet substrate 49 such as Mylar (TM). As shown with particularclarity in FIGS. 4-6, the printed circuit conductors 47 may be flowsoldered to the terminal sectionS 58 of the contact members 46.

The flash selecting system preferably contains solid state circuitryfabricated in the form of an integrated circuit (I.C.) chip 5l,the-terminals 53 of which are connected to the conductors 47. Firingcommands are supplied to the chip 51 through input/output terminals 55,also flow soldered to the conductors 47.

The printed circuit substrate 49 and the chip 51 carried thereby arepreferably supported on an extension 68 of the socket body 54. Theextension 68 defines a recess 49 for protecting the chip 51 and itsterminals 53 and terminal connections. The extension 68 also serves as aconvenient means for handling the socket assembly during fabricationthereof and during assembly into the associated photographic camera.

In accordance with the principles of this invention, I

contact means are provided for making electrical contact with terminalson the connector blade of a flash assembly 10, here shown as a set ofterminal strips 20. The contact means are shown in this embodimentcomprising a stationary set of rearwardly facing resilient contactmembers 46 arranged to engage the forwardly facing terminal strips 20 ona connector blade with a lengthwise wiping action when aconnector bladel8is inserted into the socket assembly 40.

The contact members 46 are preferably composed of a spring materialhaving high electrical conductivity and high tensile strength such ascertain well-known beryllium-copper alloys. A nickel-silver coating ispreferably applied to minimize contact resistance.

In the illustrated FIGS. l-ll embodiment, the contact members areillustrated as each including a terminal section 58, a curved section 60adapted to be anchor ed in an opening in the socket body 54, a spine 62extending upwardly from the base section 60, and a reverse-bent section64 extending from the spine 62 downwardly along the direction of bladeinsertion for making operative electrical and mechanical engagement witha terminal strip 20 on a connector blade 18 inserted into the socketassembly 40.

FIG. 10 illustrates a contact member 46 as it might appear in itsunstressed state. FIG. 11 illustrates the same contact member 46 as itmight appear if deflected and stressed by a connector blade 18 insertedinto the socket assembly 40. p

FIG. 9 illustrates the rearwardly facing interior surface of the socketenclosure. In order to electrically isolate the contact members 46 fromeach other and in order to accurately position the contact members 46 inFIGS. 12 15 illustrate an alternative embodiment of the invention; FIGS.l2, l3, and 15 are figures corresponding to FIGS. 7, l0, and 11. TheFIGS. 12-15 embodiment comprises a socket body having blade supportmeans including forward support surface means and rear support surfacemeans. The forward and rear support surface means have facing endmarginal portions 72, 73 and 74, 75, respectively, near the ends ofentrance slot 76 for firmly'engaging and supporting marginal endportions of the connector blade 18, designated 78, 80 in FIG. 5.

Considering the FIGS. 12-15 structure from another viewpoint, it can beseen that the rear support surface is recessed such that connector blade18 is loaded against the rear side marginal portions 74, 75 therebygreatly relieving the tolerance requirements which otherwise wouldnecessarily have to be maintained across the full width of the rearsupport surface. The necked end portions of the entrance slot 76 (shownwith particular clarity in FIG. 13) defined by end portions 72, 73, 74,75 have a number of other important functions. Because the socketassembly is so extremely shallow, the working length of the contactmembers is necessarily extremely short. But in order to obtain therequisite blade loading forces, the contact members 100 must have arelatively high effective spring rate. A high spring rate and a shortworking length, however, implies a relatively limited deflection ifoverstressing of the contact members 100 is to be prevented. The neckedend portions of the slot 76 act to limit pitching movement of the flashassembly 10 and thus control the stressing of the contact members 100 byconnector blade 18. As will be explained in detail below, the novelconfiguration of the contact members 100 is such as to produce arelatively high blade loading without a correspondingly high actualspring rate in the contact members 100. y

In order that the tolerance requirements may also be minimized in regardto the end-to-end dimensions of the blade-receiving space within thesocket assembly, the FIGS. l215 socket assembly includes end supportsurfaces 88, formed on lip portions 92, 94 below which are formedundercut surfaces 96, 98. By this expedient a connector blade isconfined in its side-to-side movement by the end support surfaces 88, 90only. The socket end-to-end tolerances in the FIGS. 12-15 embodimentmust be held, then, only on the end support surfaces 88, 90.

To minimize contact of the endmost terminal strips on a connectorblade18 with the socket body 70, in the FIGS. 12-15 socket assembly themaximum width Wg of each of the facing end marginal portions 72, 73, 74,75 is caused to be less than the minimum width War of the marginal endportions 78, 80 of connector blade 18.

It is a stated object of this invention to provide a flash socketassembly including contact means interfacing with the terminal strips onthe connector blade of a flash assembly in such a way as to precludemisregistration of the contact means with the terminal strips, and thusto avoid an inadvertent firing of a non-selected lamp in the flashassembly. The connector blade 18 of a flash assembly adapted for usewith socket assemblies according to this invention may be assumed tohave a determinable minimum width Y,,,,,,; the terminal strips 20 maybeassumed to have a determinable maximum width Ws and periodic spacingP.

To meet the above-stated object, the blade support means includes endsupport surfaces 88, 90 for engaging and confining opposite ends of aconnector blade 18 received in the socket assembly. The end supportsurfaces 88 90 are caused to have a maximum separation S,,,,,',,; thecontact members 100are caused to have a predetermined maximum width Wcand a periodic spacing P equal to the spacing of the terminal strips 20.By this invention the maximum separation S of the end support surfaces88, 90 is caused to be sucli insist... Ytgirsisi'tfiin P 1215.72 WCmag/Lthere by insuring that no misregistration of the contact members100 with the terminal stips 20 on a connected flash assembly will occur.

It is another stated object of this invention to provide flash socketstructures and contact means so configured and arranged as to precludeinadvertent simultaneous ignition of more than one lamp in a connectedflash lamp assembly. To this end, the maximum width Wc' of each of thecontact members 100 is caused to be less than the spacing P W, ,betweenthe terminal strips 20. By this expedient, at no time, and for norelative position of terminal strips 20 and associated contact members100, may a contact member 100 bridge two terminal strips 20'and therebycause a simultaneous ignition of more than one lamp.

The contact members 100 in the FIGS. 12-15 embodiment have a novelconvolute configuration. The generally convolute configuration of thecontact members acts to maximize the effective working length of thecontact members 100 and the tolerable deflection of the contact membersbefore overstressingoccurs. Thecontact members 100 each comprise an endsection 102, a base section 104 for connection to leads on a printedcircuit substrate 106, a spine 108, and a reverse bent section 110. Thereverse bent section 110 is illustrated as having an entrance rampportion 112, a centra portion 114, and an exit ramp portion 116.

The entrance and exit ramp portions 112, 116 assure a smooth,aesthetically pleasing insertion and withdrawal of the connector blade.The central portion 114 applies a loading force to the contiguoussurface of a connector blade in a direction normal to the connectorblade so as not to introduce any lifting force component which mighttend to raise the connector blade from the socket assembly.

As noted above, it is desirable that the force required to insert theconnector blade of a flash assembly into the socket assembly is lessthan the force required to withdraw the connector blade. To this end,contact members are each configured such that upon insertion of aconnector blade, the reverse. bent portion 110 of the contact memberoffers a predetermined resistance to deflection and introduces a knownfrictional force against the blade. The net blade insertion force iscaused to fall at a predetermined level or range of levels by anappropriate selection of thespring loading force applied by the contactmembers, the effective entry angle and configuration of the entranceramp portion 112, and the coefficients of friction between the connectorblade and the various surfaces which it engages during insertion intothe socket assembly.

The withdrawal force is caused to be greater than this insertion forceby virtue of a wedging action which is developed as the connector bladeis withdrawn. it can be seen from a study of FIG. 15, for example, thatas the connector blade 18 is withdrawn, as a result of frictional forcesdeveloped between the connector blade 18 and the reverse bent section110 of each contact member 100, the reverse bent section 110 will bedrawn along with the connector blade, thus causing the contact member100 to unroll slightly; As the contact member unrolls, its diameterexpands, causing a wedging or pinching action of the reverse bentsection 110 against the end marginal portions 74, of the rear supportsurface. By this expedient, the flash assembly 10, in spite of theextreme shallowness of the connector blade 18, is held securely againstgravitational, centrifugal, impulsive, and other forces tending todislodge the flash assembly from the socket assembly.

The contact portion 114 of each contact member is caused to be as highas possible consonant with a reasonably shallowentry angle of theentrance remp portion 112 in order that contact will be made with theterminal strips 20 on the connector blade 18 even in a situation whereina flash assembly 10 is not fully inserted into the socket assembly. 7

As discussed above, it is desirable that the contact members 100 have arelatively low spring rate in order to minimize the likelihood ofoverstressing, and yet it is also desirable that the contact members 100develop a relatively high blade loading force. To thisend, contactmembers 100 include a tip section 117 extending from the reverse bentsection .110; into engagement with the spine 108 to increase theeffective spring rate of the contact members 100. By this expedient, arelatively great blade loading force can be developed in a contactmember having a relatively low spring rate,

thus minimizing the chance that overstressing of the contact members 100might occur. Minimization of the spring rate of the contact members 100is also advantageous in that the wear rate of the contact members 100and thus the change in the spring rate thereof dueto wear, arecorrespondingly minimized.

As discussed above, it is extremely important that contact resistance ofthe contact members 100' engaging the terminal strips 20 be minimized.Minimization of the contact resistance is achieved by virtue of thewiping of the terminal strips 20 by the contact members as a connectorblade is inserted into the socket assembly, the wiping action serving tokeep the terminalcontact member interfacing surfaces clean.

As described in'some ,detail above, the contact members 100 not onlyfunction to electrically interface the flash assembly 10' with the flashselecting system22,

but also serve to apply a loading force against the connector blade of aflash assembly inserted into the socket assembly.lt is important thattheblade loading force hold the connector blade 18 securely and stablyagainst the above-described rear support surface acting as an alignmentplane of reference.

However, the extreme shallowness of the connector blade 18, the radiuson the free corners 118 and 120 of the blade, the radius R" on thebottom edge of the blade 18, and the bevel depth d of the beveled mouth122 surrounding the entrance slot 76 in the socket body 70 conspireagainst the achievement of a stable support for a connector bladeagainst the rear support surface in the socket assembly. It can be seenthat the primary constraint is the extremely limited blade depth Dnecessitated. by the stringent space limitations imposed on the socketbody 70 by the compactness of the associated photographic camera.

It can also be seen that the radius R of the bottom edge of the blade18, necessary to facilitate insertion of the connector blade 18 into theentrance slot 76 and to eliminate sharp edges, reduces the blade areawhich may engage the end marginal portions 74, 75 of the socket rearsupport surface. The bevel depth d of the outwardly beveled mouth 122also acts negatively to reduce the area of interface between the endmarginal portions 74, 75 and the blade 18. The combination of thesethree-primary factors severely restricts the ability of the bladeloading means, here shown as the contact members 100, to hold theconnector blade securely against the rear support surface provided bythe socket assembly.

In accordance with an aspect of this invention, the contact portions 114of the contact members 100 are caused to be aligned and to act on aninserted connector blade 18 in alongitudinally oriented force-receivingarea on the blade having depthwise boundaries of D(R+d). By thisexpedient, optimum stability of the connector blade 18 in the socketassembly, and thus optimum stability of the flash array 10, is assured.

In order to allow presetting of the contact members so as to increasethe blade loading forces developed thereby while assuring mutualalignmentof the contact members even if unequally prestressed, thesocket assemblies include limiter means for abutting the contact membersto define arearward limit position thereof. The limiter means takes theform of a wedge-shaped projection formed integrally with the socket bodywhich engages the entrance ramp portions of the contact members. Otherstructures for accomplishing the desired limiting and aligning functionsare contemplated.

The invention isnot limited to the particular details of construction ofthe embodiments depicted, and it is contemplated that various and othermodifications and applications will occur to those skilled in the art.Therefore, because'certain changes may be made in the above-describedapparatus without departing from the true spirit and scope of theinvention herein involved, it is intended that the'subject matter of theabove dcpiction shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:

l. A photographic camera including a lens having a picture-taking axis,a socket assembly for'receiving and retaining a multilamp flash assemblyhaving an array of lamps facing in a common direction and in thedirection of said picture-taking axis and a supporting structure fromwhich extends a connector blade carrying on a face thereof oriented insaid common direction a set of spaced electrical terminal strips for thelamps in said array arranged in parallel along the direction ofinsertion of the flash assembly into said socket assembly, the bladebeing generally rectangular and of a depth D substantially less than itswidth Y with its bottom edge having a radius R, said camera comprising:

means defining an entrance slot for the connector blade of the flashassembly which is perpendicular to said picture-taking axis of thecamera, said entrance slot being surrounded by an inwardly beveled mouthof effective bevel depth d";

blade support means for guiding the connector blade from said entranceslot into an operative position within said socket assembly wherein theface of the blade carrying the terminal strips faces forwardly in thedirection of said picture-taking axis, said blade support meansincluding rear support surface means adapted to be engaged by the bladefor assisting in supporting the blade in said operative po- 1 -sition; v

contact means for making electrical contact with the terminal strips onthe connector blade comprising a stationary set of parallel andrearwardly-facing resilient contact members arranged to register withand to engage the terminal strips with a lengthwise wiping action whenthe connector blade is inserted into said socket assembly, said contactmembers having aligned operative contact portions acting on the blade ina longitudinally oriented forcereceiving area on the blade havingmaximum depthwise boundaries of maximum length D-R and d which extendbetween d and R, as taken with respect to a blade fully connected insaid socket assembly, such that the blade is held securely and withstability against said rear support surface means acting as an alignmentplane of reference.

2. The apparatus as defined by claim 1 wherein said contact members eachhave a maximum'width Wa which is less than the minimum space between twoadjacent terminal strips whereby engagement of more than one terminalstrip by any contact member ispreeluded.

3. The apparatus defined by claim 1 wherein said contact members eachinclude a base section for connection to a support surface at the bottomof abladeoccupying space within said socket assembly, a spine extendingupwardly from said base section, and a reverse bent section extendingfrom said spine downwardly along the direction of blade insertion formaking operative electrical and mechanical engagement with a terminalstrip on a connector blade inserted into said socket assembly.

4. The apparatus defined by claim 3 wherein said contact members eachadditionally, have a tip section extending from said reverse bentsection into engagement with said spine for increasing the effectivespring rate of said contact members.

5. The apparatus defined by claim 1 wherein said blade support meansdefines opposed end support surfaces having lip portions, one adjacentand beneath each end of said entrance slot for engaging opposite ends ofa connector blade received in said socket assembly, said end supportsurfaces being undercut below said lip portions to cause said endsupport sur- 7. The apparatus defined by claim l'including insulative'spacing means forphysically and electrically separating said con'tactmembers and for establishing and maintaining accurate alignment of saidcontact members with the terminal strips of the connector blade of aflash assembly inserted into said socket assembly.

1. A photographic camera including a lens having a picturetaking axis, asocket assembly for receiving and retaining a multilamp flash assemblyhaving an array of lamps facing in a common direction and in thedirection of said picture-taking axis and a supporting structure fromwhich extends a connector blade carrying on a face thereof oriented insaid common direction a set of spaced electrical terminal strips for thelamps in said array arranged in parallel along the direction ofinsertion of the flash assembly into said socket assembly, the bladebeing generally rectangular and of a depth ''''D'''' substantially lessthan its width ''''Y'''' with its bottom edge having a radius ''''R'''',said camera comprising: means defining an entrance slot for theconnector blade of the flash assembly which is perpendicular to saidpicture-taking axis of the camera, said entrance slot being surroundedby an inwardly beveled mouth of effective bevel depth ''''d''''; bladesupport means for guiding the connector blade from said entrance slotinto an operative position within said socket assembly wherein the faceof the blade carrying the terminal strips faces forwardly in thedirection of said picture-taking axis, said blade support meansincluding rear support surface means adapted to be engaged by the bladefor assisting in supporting the blade in said operative position;contact means for making electrical contact with the terminal strips onthe connector blade comprising a stationary set of parallel andrearwardly-facing resilient contact members arranged to register withand to engage the terminal strips with a lengthwise wiping action whenthe connector blade is inserted into said socket assembly, said contactmembers having aligned operative contact portions acting on the blade ina longitudinally oriented force-receiving area on the blade havingmaximum depthwise boundaries of maximum length D-R and d which extendbetween d and R, as taken with respect to a blade fully connected insaid socket assembly, such that the blade is held securely and withstability against said rear support surface means acting as an alignmentplane of reference.
 2. The apparatus as defined by claim 1 wherein saidcontact members each have a maximum width Wc which is less than theminimum space between two adjacent terminal strips whereby engagement ofmore than one terminal strip by any contact member is precluded.
 3. Theapparatus defined by claim 1 wherein said contact members each include abase section for connection to a support surface at the bottom of ablade-occupying space within said socket assembly, a spine extendingupwardly from said base section, and a reverse bent section extendingfrom said spine downwardly along the direction of blade insertion formaking operative electrical and mechanical engagement with a terminalstrip on a connector blade inserted into said socket assembly.
 4. Theapparatus defined by claim 3 wherein said contact members eachadditionally have a tip section extending from said reverse bent sectioninto engagement with said spine for increasing the effective spring rateof said contact members.
 5. The apparatus defined by claim 1 whereinsaid blade support means defines opposed end support surfaces having lipportions, one adjacent and beneath each end of said entrance slot forengaging opposite ends of a connector blade received in said socketassembly, said end support surfaces being undercut below said lipportions to cause said end suppOrt surfaces to engage the connectorblade only at said lip portions.
 6. The apparatus defined by claim 1wherein said contact members exert a predetermined loading on theconnector blade received in said socket assembly producing frictionalforces which are effective to retain the flash assembly securely in saidsocket assembly.
 7. The apparatus defined by claim 1 includinginsulative spacing means for physically and electrically separating saidcontact members and for establishing and maintaining accurate alignmentof said contact members with the terminal strips of the connector bladeof a flash assembly inserted into said socket assembly.